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Coordinate activities of BRD4 and CDK9 in the transcriptional elongation complex are required for TGFβ-induced Nox4 expression and myofibroblast transdifferentiation. Cell Death Dis 2017; 8:e2606. [PMID: 28182006 PMCID: PMC5386453 DOI: 10.1038/cddis.2016.434] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/15/2016] [Accepted: 11/22/2016] [Indexed: 12/19/2022]
Abstract
Transdifferentiation of quiescent dermal fibroblasts to secretory myofibroblasts has a central role in wound healing and pathological scar formation. This myofibroblast transdifferentiation process involves TGFβ-induced de novo synthesis of alpha smooth muscle cell actin (αSMA)+ fibers that enhance contractility as well as increased expression of extracellular matrix (ECM) proteins, including collagen and fibronectin. These processes are mediated upstream by the reactive oxygen species (ROS)-producing enzyme Nox4, whose induction by TGFβ is incompletely understood. In this study, we demonstrate that Nox4 is involved in αSMA+ fiber formation and collagen production in primary human dermal fibroblasts (hDFs) using a small-molecule inhibitor and siRNA-mediated silencing. Furthermore, TGFβ-induced signaling via Smad3 is required for myofibroblast transformation and Nox4 upregulation. Immunoprecipitation-selected reaction monitoring (IP-SRM) assays of the activated Smad3 complex suggest that it couples with the epigenetic reader and transcription co-activator bromodomain and extraterminal (BET) domain containing protein 4 (BRD4) to promote Nox4 transcription. In addition, cyclin-dependent kinase 9 (CDK9), a component of positive transcription elongation factor, binds to BRD4 after TGFβ stimulation and is also required for RNA polymerase II phosphorylation and Nox4 transcription regulation. Surprisingly, BRD4 depletion decreases myofibroblast differentiation but does not affect collagen or fibronectin expression in primary skin fibroblasts, whereas knockdown of CDK9 decreases all myofibroblast genes. We observe enhanced numbers and persistence of myofibroblast formation and TGFβ signaling in hypertrophic scars. BRD4 inhibition reverses hypertrophic skin fibroblast transdifferentiation to myofibroblasts. Our data indicate that BRD4 and CDK9 have independent, coordinated roles in promoting the myofibroblast transition and suggest that inhibition of the Smad3-BRD4 pathway may be a useful strategy to limit hypertrophic scar formation after burn injury.
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Shen C, Jiang L, Shao H, You C, Zhang G, Ding S, Bian T, Han C, Meng Q. Targeted killing of myofibroblasts by biosurfactant di-rhamnolipid suggests a therapy against scar formation. Sci Rep 2016; 6:37553. [PMID: 27901027 PMCID: PMC5128858 DOI: 10.1038/srep37553] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 11/01/2016] [Indexed: 01/06/2023] Open
Abstract
Pathological myofibroblasts are often involved in skin scarring via generating contractile force and over-expressing collagen fibers, but no compound has been found to inhibit the myofibroblasts without showing severe toxicity to surrounding physiological cells. Here we report that di-rhamnolipid, a biosurfactant secreted by Pseudomonas aeruginosa, showed potent effects on scar therapy via a unique mechanism of targeted killing the myofibroblasts. In cell culture, the fibroblasts-derived myofibroblasts were more sensitive to di-rhamnolipid toxicity than fibroblasts at a concentration-dependent manner, and could be completely inhibited of their specific functions including α-SMA expression and collagen secretion/contraction. The anti-fibrotic function of di-rhamnolipid was further verified in rabbit ear hypertrophic scar models by presenting the significant reduction of scar elevation index, type I collagen fibers and α-SMA expression. In this regard, di-rhamnolipid treatment could be suggested as a therapy against skin scarring.
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Affiliation(s)
- Chong Shen
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, PR China
| | - Lifang Jiang
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, PR China
| | - Huawei Shao
- Department of Burns &Wound Care Centre, Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, PR China
| | - Chuangang You
- Department of Burns &Wound Care Centre, Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, PR China
| | - Guoliang Zhang
- Ocean College, Zhejiang University of Technology, Hangzhou, PR China
| | - Sitong Ding
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, PR China
| | - Tingwei Bian
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, PR China
| | - Chunmao Han
- Department of Burns &Wound Care Centre, Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou, PR China
| | - Qin Meng
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, PR China
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Wu T, Chen X, Peng R, Liu H, Yin P, Peng H, Zhou Y, Sun Y, Wen L, Yi H, Li A, Zhang Z. Let‑7a suppresses cell proliferation via the TGF‑β/SMAD signaling pathway in cervical cancer. Oncol Rep 2016; 36:3275-3282. [PMID: 27748903 DOI: 10.3892/or.2016.5160] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/08/2016] [Indexed: 11/05/2022] Open
Abstract
Cervical cancer is the second most commonly diagnosed type of cancer among women after breast cancer. Recent research has addressed the role of microRNAs in cervical cancer. In the present study, we aimed to determine the effect of let‑7a on the regulation of the cell proliferation of cervical cancer and the related signaling pathway. Real‑time RT‑PCR was used to detect the expression of let‑7a in the blood of cervical cancer patients and normal controls. The expression of let‑7a was also assessed in cervical cancer cell lines: HeLa, SiHa and normal human immortalized keratinocyes HaCaT. Cell proliferation was tested by MTT assay, and cell apoptosis and cell cycle were examined by flow cytometric analysis in HeLa cells. Moreover, bioinformatic analysis, dual‑luciferase reporter assay and western blotting were used to confirm the target gene for let‑7a. In addition, the expression of TGF‑β1, SMAD4 and p53 were assessed by western blotting and real‑time PCR. Our studies showed that the expression of let‑7a in cervical cancer was significantly reduced in cervical cancer patients compared with the expression in the normal control group. Cell proliferation of HeLa cells was inhibited by overexpression of let‑7a. The cell cycle analysis showed that an increased population was arrested in the G2 phase in the let‑7a mimic group when compared with that in the mimic control and untreated groups. In addition, the cell cycle‑related factor p53 was increased in the let‑7a overexpression group compared with that in the control and untreated groups. Furthermore, TGFBR1 was confirmed to be a target of let‑7a. Moreover, the expression of TGF‑β1 and SMAD4 proteins was elevated in cervical squamous carcinoma and cervical adenocarcinoma tissues. However, the expression of TGF‑β1 and SMAD4 was decreased in the let‑7a‑overexpressing cervical cancer cell lines (HeLa, SiHa and CaSki). Our data suggest that let‑7a may play a role in the cell proliferation of cervical cancer by regulating the TGF‑β/SMAD pathway, and may participate in the regulation of the occurrence and development of cervical cancer.
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Affiliation(s)
- Tianhui Wu
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Xin Chen
- Department of Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400010, P.R. China
| | - Rui Peng
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Handeng Liu
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Pin Yin
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Huimin Peng
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Yujian Zhou
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Yan Sun
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Li Wen
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Hong Yi
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Ailing Li
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
| | - Zheng Zhang
- Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, P.R. China
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Growth factor pathways in hypertrophic scars: Molecular pathogenesis and therapeutic implications. Biomed Pharmacother 2016; 84:42-50. [PMID: 27636511 DOI: 10.1016/j.biopha.2016.09.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 08/26/2016] [Accepted: 09/05/2016] [Indexed: 01/07/2023] Open
Abstract
Hypertrophic scars represent the most common complication of skin injury and are caused by excessive cutaneous wound healing characterized by hypervascularity and pathological deposition of extracellular matrix (ECM) components. To date, the optimal and specific treatment methods for hypertrophic scars have not been available in the clinic. Current paradigm has established fibroblasts and myofibroblasts as pivotal effector cells in the pathophysiology of wound healing. Their biological properties including origin, proliferation, migration, contraction and ECM regulation have profound impacts on the progression and regression of hypertrophic scars. These complex processes are executed and modulated by a signaling network involving a number of growth factors and cytokines. Of particular importance is transforming growth factor-β, platelet-derived growth factor, connective tissue growth factor, epidermal growth factor, and vascular endothelial growth factor. This review article briefly describes the biological functions of fibroblasts and myofibroblasts during hypertrophic scars, and thereafter examines the up-to-date molecular knowledge on the roles of key growth factor pathways in the pathophysiology of hypertrophic scars. Importantly, the therapeutic implications and future challenges of these molecular discoveries are critically discussed in the hope of advancing therapeutic approaches to limit pathological scar formation.
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Wang P, Liu X, Xu P, Lu J, Wang R, Mu W. Decorin reduces hypertrophic scarring through inhibition of the TGF-β1/Smad signaling pathway in a rat osteomyelitis model. Exp Ther Med 2016; 12:2102-2108. [PMID: 27698699 PMCID: PMC5038452 DOI: 10.3892/etm.2016.3591] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/27/2016] [Indexed: 12/31/2022] Open
Abstract
Chronic osteomyelitis is a bone infection that results in hypertrophic scarring of the soft tissue surrounding the infected bone. This scarring can create functional problems and its treatment is challenging. The aim of the present study was to evaluate the efficacy of decorin in treating scar formation in osteomyelitis and the underlying mechanism of its action. A rat osteomyelitis model was used, and animals were divided into three groups, as follows: Group A (control), group B (osteomyelitis model) and group C (decorin-treated). X-ray scans, hematoxylin and eosin (H&E) staining and Masson's trichrome staining were performed to observe changes in femur and muscle tissue. In order to assess the role of the transforming growth factor β1 (TGF-β1)/Smad signaling pathway in scar formation in osteomyelitis, alterations in muscle tissue morphology and in the activation of key members of the TGF-β1/Smad signaling pathway were investigated in groups A and B. According to the results of H&E staining, evident fibrosis in muscle tissue were observed at days 14 and 28 in group B. Simultaneously, the expression levels of key members of the TGF-β1/Smad signaling pathway were increased. Subsequent to treatment with decorin in group C, scarring was reduced, and significant downregulation of collagen I, TGF-β1, phosphorylated (p)Smad2 and pSmad3 protein expression levels was observed at days 14 and 28 compared with the osteomyelitis group. In conclusion, these results suggest that activation of TGF-β1 may serve an important role in the formation of scars in osteomyelitis and that decorin can reduce scar formation in an osteomyelitis rat model through inhibition of the TGF-β1/Smad signaling pathway.
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Affiliation(s)
- Peng Wang
- Department of Traumatic Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250012, P.R. China; Department of Orthopaedics, Weihai Municipal Hospital, Weihai, Shandong 264200, P.R. China
| | - Xiangyan Liu
- Department of Thoracic Surgery, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250012, P.R. China
| | - Peng Xu
- Department of Traumatic Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250012, P.R. China
| | - Jialiang Lu
- Department of Traumatic Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250012, P.R. China
| | - Runze Wang
- Department of Traumatic Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250012, P.R. China
| | - Weidong Mu
- Department of Traumatic Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, Shandong 250012, P.R. China
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Zhao J, Shu B, Chen L, Tang J, Zhang L, Xie J, Liu X, Xu Y, Qi S. Prostaglandin E2 inhibits collagen synthesis in dermal fibroblasts and prevents hypertrophic scar formation in vivo. Exp Dermatol 2016; 25:604-10. [PMID: 26997546 DOI: 10.1111/exd.13014] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/29/2016] [Indexed: 01/07/2023]
Abstract
Hypertrophic scarring is a common dermal fibroproliferative disorder characterized by excessive collagen deposition. Prostaglandin E2 (PGE2 ), an important inflammatory product synthesized via the arachidonic acid cascade, has been shown to act as a fibroblast modulator and to possess antifibroblastic activity. However, the mechanism underlying the antifibrotic effect of PGE2 remains unclear. In this study, we explored the effects of PGE2 on TGF-β1-treated dermal fibroblasts in terms of collagen production and to determine the regulatory pathways involved, as well as understand the antiscarring function of PGE2 in vivo. We found that PGE2 inhibited TGF-β1-induced collagen synthesis by regulating the balance of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP). It did so by upregulating cAMP through the E prostanoid (EP)2 receptor. We determined that inhibition of the TGF-β1/Smad pathway by PGE2 is associated with its ability to inhibit collagen synthesis. An in vivo study further confirmed that PGE2 inhibits hypertrophic scar formation by decreasing collagen production. Our results demonstrate that the novel anti-scarring function of PGE2 is achieved by balancing MMPs/TIMP expression and decreasing collagen production.
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Affiliation(s)
- Jingling Zhao
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Bin Shu
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Lei Chen
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Jinming Tang
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Lijun Zhang
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Julin Xie
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xusheng Liu
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Yingbin Xu
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Shaohai Qi
- Department of Burns, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
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Growth Hormone-Releasing Peptide 6 Enhances the Healing Process and Improves the Esthetic Outcome of the Wounds. PLASTIC SURGERY INTERNATIONAL 2016; 2016:4361702. [PMID: 27200188 PMCID: PMC4854984 DOI: 10.1155/2016/4361702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/28/2016] [Indexed: 01/25/2023]
Abstract
In addition to its cytoprotective effects, growth hormone-releasing peptide 6 (GHRP-6) proved to reduce liver fibrotic induration. CD36 as one of the GHRP-6 receptors appears abundantly represented in cutaneous wounds granulation tissue. The healing response in a scenario of CD36 agonistic stimulation had not been previously investigated. Excisional full-thickness wounds (6 mmØ) were created in the dorsum of Wistar rats and topically treated twice a day for 5 days. The universal model of rabbit's ears hypertrophic scars was implemented and the animals were treated daily for 30 days. Treatments for both species were based on a CMC jelly composition containing GHRP-6 400 μg/mL. Wounds response characterization included closure dynamic, RT-PCR transcriptional profile, histology, and histomorphometric procedures. The rats experiment indicated that GHRP-6 pharmacodynamics involves attenuation of immunoinflammatory mediators, their effector cells, and the reduction of the expression of fibrotic cytokines. Importantly, in the hypertrophic scars rabbit's model, GHRP-6 intervention dramatically reduced the onset of exuberant scars by activating PPARγ and reducing the expression of fibrogenic cytokines. GHRP-6 showed no effect on the reversion of consolidated lesions. This evidence supports the notion that CD36 is an active and pharmacologically approachable receptor to attenuate wound inflammation and accelerate its closure so as to improve wound esthetic.
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Zhang X, Yang J, Zhao J, Zhang P, Huang X. MicroRNA-23b Inhibits the Proliferation and Migration of Heat-Denatured Fibroblasts by Targeting Smad3. PLoS One 2015; 10:e0131867. [PMID: 26153982 PMCID: PMC4496062 DOI: 10.1371/journal.pone.0131867] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 06/09/2015] [Indexed: 01/07/2023] Open
Abstract
Background Skin grafting with the preservation of denatured dermis is a novel strategy for the treatment of burn-injured skin. Denatured dermis has the ability to restore to the morphology and function of normal skin, but the underlying molecular mechanism is elusive. MicroRNAs (miRNA) are small noncoding RNAs and regulate normal physiology as well as disease development. In this study, we assessed the potential role of miRNA-23b (miR-23b) in the regulation of cell proliferation and migration of heat-denatured fibroblasts and identified the underlying mechanism. Methods The expression of miR-23b in denatured dermis and heat-denatured fibroblasts was detected by quantitative real-time polymerase chain reaction (RT-PCR). The effects of miR-23b on cell proliferation and migration of heat-denatured fibroblasts were assessed by transient transfection of miR-23b mimics and inhibitor. The target gene of miR-23b and the downstream pathway were further investigated. Results miR-23b was downregulated in denatured dermis and heat-denatured fibroblasts. Downregulation of miR-23b dramatically promoted the proliferation and migration of heat-denatured fibroblasts. Subsequent analyses demonstrated that Smad3 was a direct and functional target of miR-23b in heat-denatured fibroblasts, which was validated by the dual luciferase reporter assay. Moreover, immunohistochemistry analysis showed that denatured dermis from rats displayed enhanced staining of Smad3. In addition, miR-23b modulated denatured dermis by activating the Notch1 and TGF-β signaling pathways. Conclusions Our findings suggest that downregulation of miR-23b contributes to the recovery of denatured dermis, which may be valuable for treatment of skin burns.
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Affiliation(s)
- Xipeng Zhang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Jie Yang
- Department of Pathology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510282, China
| | - Jiming Zhao
- Department of Traditional Chinese Medicine, Jinzhou Traditional Chinese Medicine Hospital, Zhangjiajie, Hunan 427000, China
| | - Pihong Zhang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - Xiaoyuan Huang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
- * E-mail:
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